ATX12V 2.0 - 24 pin main connector, 4 pin secondary connector (Pentium 4, Core 2 Duo, and Athlon 64 with PCI Express)
ATX12V 2.2 - One 20/24-pin connector, one ATX12V 4 pin connector. Many power supply manufacturers include a 4 plus 4 pin, or 8 to 4 pin secondary connector instead, which can also be used as the secondary EPS12V connector.